It is a problem in the field of Air-To-Ground (ATG) communications, such as between aircraft and ATG ground stations, to provide sufficient bandwidth to carry the communications between the communication devices, which are served by a communication network (wired or wireless) located on the aircraft, and ATG ground stations which are connected to terrestrial communication networks. The collection of ATG ground stations used for this purpose implement a traditional cellular network, with each ATG ground station consisting of a “cell site.” There are limited choices of spectrum which are available for this purpose, which choices are also limited by the ability to implement the corresponding radio frequency antennas on the aircraft.
The typical ATG cellular communications network consists of a number of terrestrial (ground) ATG base stations, each of which provides a radio frequency coverage area in a predetermined volume of space, radially arranged around the cell site transmitting and receiving antennas. This terrestrial base station uses antenna patterns which are less sensitive to the reception of ground-originating or ground-reflected signals and which antenna patterns are primarily focused on the area between the horizon and zenith. The terrestrial base stations are geographically distributed, generally following a typical cellular communications network layout. Terrestrial base stations can also be co-located near airports to enable network coverage when aircraft are on the ground; in this case, the antenna patterns are optimized for terrestrially-located aircraft. The boundaries of the coverage area of each terrestrial base station are substantially contiguous with that of neighboring sites so that the composite coverage of all of the terrestrial base stations in the ATG cellular communications network generally provides coverage over the targeted area. Terrestrial base stations may provide either a single omni-cell of coverage using transceiver(s) associated with a single transmit-and-receive antenna system or multiple sectors within the area of coverage of the site, each with associated transceivers and the associated transmit-and-receive antennas. The advantage of the latter arrangement, with multiple sectors per terrestrial base station, is to allow provision of increased call and data traffic handling capacity in the coverage area of that terrestrial base station.
The present radio frequency spectrum which is available for this purpose limits the total available traffic handling capacity in any single cell. Thus, the radio frequency communications link between the aircraft and the terrestrial base stations of the ATG cellular communications network has limited capacity and, as passengers utilize the aircraft network for Internet browsing and broadband file downloads, the channel capacity becomes exhausted before the demand is served in its entirety. More advantageous spectrum choices are presently unavailable, because they are dedicated for pre-existing uses, such as satellite communications.